Apparatus for heat-treating wheels



H. B. WISHART 2,535,]! l

APPARATUS FOR HEAT-TREATING WHEELS Dec. 26, 1950 Original Filed Feb. 28,1946 6 Sheets-Sheet 1 'W/WW/WWWAQ&

INVENTOR.

Ham/0 5. M's/20M H. B. WISHART APPARATUS FOR HEAT-TREATING WHEELS Dec.26, 1950 6 Sheets-Sheet 2 Original Filed Feb. 28 1946 INVENTOk. 17'0/0/0B. Mafia/"6 11/5 ATTORNEY Dec. 26, 1950 H. a. WI$HART APPARATUS FORFEAT-TREATING mums s Sheets-Shef 3 Original Filed Feb. 28, 1946 I r n.I. Z I J /I i. \i n u vl 5 VII III/21,7 5

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INVENTOR. Ham/d B. Misha/T H. B. WIS'HART APPARATUS FOR FEAT-TREATINGWHEELS Original Filediob; 28, 1946 Dec. 26, 1950' '6 Sheets-Sheet 4INVENTOR Ham/0 B. Wishart HIS ATTORNEY Dec. 26, 1950 H. B. WISHARTAPPARATUS FOR FEAT-TREATING WHEELS Original Filed Feb. 28, 1946 6Sheets-Sheet 5 fid/hwr/ H/S ATTOR EY Dec. 26, 1950 H. a. WISHARTAPPARATUS FOR HEAT-TREATING WIIEELS 6 Sheets-Shes 6 Original Filed Feb.28, 1946- INVENTOR. Ham/0 B. M'J/YQ/ Patented Dec. 26, 1950 APPARATUSFOR HEAT-TREATING WHEELS Harold B. Wishart, Gary, Ind., assignor toCarnegie-Illinois Steel Corporation, a corporation of New JerseyOriginal application February 28, 1946, Serial No. 650,987. Divided andthis application October 11, 1946, Serial No. 702,623

14 Claims. (Cl. 134-105) This invention relates to an apparatus for heattreating metal wheels, particularly steel railway wheels, to obtaindesired properties in the various parts thereof.

The invention has among its object the provision of an apparatus forcarrying out the heat treatment of the various parts of such wheels in apredetermined sequence, so that the heat treating cycle may be effectedquickly and accurately. This apparatus displays particular advantageswhen employed in carrying out the heat treating method disclosed andclaimed in my copending application Serial No. 650,987, filed February28, 1946, of which this is a division.

Wheels for rolling stock, such as railway cars, particularly those usedin modern high speed railway tramc, should, in order to be reasonablylight while still providing an adequate safety factor, have the variousparts thereof provided with quite diilerent physical characteristics.This is necessary because of the difl'erent conditions encountered bythe several parts in service and the necessary further processing of thewheel after heat treating. Thus, the tread which engages the rail and issubject to rapid heating upon the application of the brakes must beresistant to wear and to thermal shock. The portion of the hub of thewheel immediately surrounding the bore, which must be machined afterheat treating of the wheel for the reception of the axle and of variousbearing members, if such are used, should preferably remain machinableafter the heat treating of the wheel. The web plate which connects thehub to the tread should be resilient and resistant to fatigue since itis subjected to flexing during use.

Since it is most feasible to form such wheels integrally and later toproduce the different characteristics where desired in the variousparts, it has been found necessary to employ heat treatments which leavesuch parts in conditions at least pointing toward the optimum conditionsset out above. The wheel making industry has in general employed twomethods of heat treating wheels for this purpose, the first of whichcomprises oil quenching the entire wheel from an austenitizingtemperature, and the second of which comprises water quenching the rimand to some extent the hub from austenitizing temperature, known as therim toughening process. In both such methods the wheels are given a timequench and are not quenched to room temperature; Neither of the aboveprior methods is entirely satisfactory because, while producingdesirable qualities in one portion of the wheel in far from the bestcondition. For instance, the oil quenching brings out the fatigueresistant quality of the metal which is desirable for the plate, butdoes not bring out the desirable qualities necessary for the wheeltread. The water quench, on the other hand, brings out the bestqualities for the tread, with no increase in the physical properties ofthe plate for fatigue resistance. .In addition to the increase inphysical values obtained by quenching, the residual stresses produced inthe wheels by such treatment are of importance. The rim tougheningprocess produces residual stresses which offer greater resistance tothermal cracking in the rim and greater resistance to plate failure asproduced by brake application than the oil quenched wheels.

Because of the known disadvantages of such two prior methods, variouscompromise methods have been proposed. Among these is one employingdifferential quenching of the rim, plate, and major portion of the hub.

The apparatus of the present invention when employed in carrying out theheat treating method disclosed and claimed in application Serial No.650,987 permits the production of a wheel of the type described in whichsubstantially the best physical characteristics are present in eachpart. Thus, such wheel has a tough wearing tread which is resistant tothermal shock, a web plate which is strong and resilient to meet the carand dynamic loads thereby minimizing fatigue failure, and a hub which iseasily machinable. The heat treating method of the copending applicationconsists broadly in dividing the wheel into quenching zones andproviding independent quenching of the various zones, such quenchingsbeing arranged in a sequence which will secure the best overall results.In addition, such dividing of the wheel into zones makes possible theuse of various quenchingtechniques on the several zones, such quenchingsbeing carried out in different sequences or combinations. As an exampleof one member in which the invention may be carried out, the tread maybe water spray quenched and then the entire wheel submerged in an oilbath to quench the plate. The appara-'- tus of the present inventionprovides a means for performing such method wherein the wheels may beprogressively quenched in the various zones. The apparatus furtherprovides means for supplying the web plate of the wheel, if necessary,with supplementary heat during quenching of the rim to prevent the webplate from falling below. the critical point before it is subjected tothey leave another portion. or the other portions, quenching.

the wheel gripping and manipulating device employed during the heattreating, the section being taken along the line III--III in Figure 5;

Figured is a view in vertical section through the gripper andmanipulator, the section being taken along the line IVIV in Figure 3;

Figure 5 is a view in horizontal section through the gripper andmanipulator, the section being taken along the line V--V in Figure 3;

Figure 6 is a diagrammatic view in vertical section illustrating thefirst part of an alternative method employing only water quenching;

Figure 6 is a view similar to that of Figure 6 but showing the wheel inthe second, plate quenching, position of such first alternative method;

Figure 7 is a view similar to Figure 6 but showing the wheel submergedto another alternative second, web plate quenching, position in thewater bath;

Figure 8 is a diagrammatic view in vertical section through a wheelillustrating a still further alternative second, plate quenching, methodemploying water sprays;

Figure 9 is a view in vertical section through a modification of thewheel gripper and manipulator adapted for use with oil quenching aloneof the wheel, the section being taken along the line IX-IX of Figure 11;

Figure 10 is a view in end elevation of the wheel and the gripper shownin Figure 9, the view being taken from the line X-f-X in Figure 9;

Figure 11 is a view in horizontal section through the gripper andmanipulator of Figure 9, the section being taken along the line XI-XI ofFigure 9;

Figure 12 is a diagrammatic view in vertical section through the wheelshowing the wheel in its, first, rim quenching, P sition in the oilbath; and

Figure 12 is a similar diagrammatic view showing such wheel in second,plate quenching, position in the oil bath.

In heat treating'a wheel in accordance with the method disclosed andclaimed in application Serial No. 650,987 the wheel is uniformly heatedthroughout its extent to a point above its transformation temperature,and is then removed from the furnace. In the preferred embodiment ofsuch method, the wheel is first water quenched for a predetermined timeon the rim while the plate and hub are shielded from contact with thequenching water spray or water bath, and additional heat is supplied, ifnecessary, to the plate to maintain it above the transformation point.The wheel is then transferred to an oil quenching bath in which it issubmerged to quench the plate for a predetermined time, so that optimumproperties are imparted to the rim and plate. The apparatus shownsomewhat schematically in Figures 1 and 2 and in greater detail inFigures 3, 4, and 5 has proved eminently satisfactory for the carryingout of such preferred method.

In Figures 1 and 2 there is shown a tank 2 containing a water bath 24which is maintained at a predetermined level, as by means of aconventional overflow device (not shown). In line with tank 2 but spacedsomewhat from it as shown, there is a further tank 4 containing an oilquenching bath 26. The wheel to be heat treated. which is designated I2,is mounted at the heat treating station in a wheel gripping andmanipulating device, generally designated 6, consisting of an arm on theouter end of which is secured a gripping head, the inner end of the armbeing mounted on horizontal shaft 8 between tanks 2 and 4 and journaledin bearings l0, which are located beyond the tanks as shown in Figure l.The device 6 is thus so mounted that its outer end, and consequentlywheel I! gripped thereby, may be positioned in any one of a variety ofpositions, from a location in which the wheel is fully submerged in thewater bath to one 'in' which it is fully submerged in the oil bath, bythe turning of shaft 8 and consequently of the arm. Such turning of thearm may be accomplished by means of a motor I4 connected to a speedreducing gear box I6 which drives a sprocket 20. The shaft 8 is drivenby sprocket 20 through a chain 22 traversing a sprocket l8 on the outerend of shaft 8. Motor [4, which is provided with conventional starting,stopping, and reversing controls as well as an electromagnetic brake,none of which is shown, may thus be made to swing the device 6 into anydesired position, within the limits named, to permit loading of thedevice with the heated wheel l2 when it is raised to the position abovetank 2, shown in Figure 2, to permit quenching of the rim or treadportion of the wheel when it is lowered toward the water bath, also asshown in Figure 2, and to permit further quenching of the rim andquenching of the plate when it is swung over to submerge the wheel inthe oil bath 26, The degree to which the wheel may be submerged in thewater bath may be accurately determined by providing suitable adjustablestop means (not shown) engagin the arm of device 6 to limit the degreeof approach thereof toward the upper surface of the water bath, which, aabove explained, is held at a constant level.

The gripper and manipulator device 6 is supplied with heated wheels andis unloaded after completion of the quenching operations on the wheel bymeans such as gripper 28, shown in Figures 1 and 2, which provides tongsfor engaging the rim of the wheel to transfer it from the furnace togripper 6, and from gripper 6 to a subsequent working station. Thegripper may conveniently be mounted upon a conventional telpher crane.

The gripper and manipulator 6, as more fully shown in Figures 3, 4, and5, comprises a supporting arm 30. Attached to shaft 8 at a positionbeyond the oil tank 4 is a rearwardly directed counterweight arm 32having depending links 34 attached to the outer end thereof. To thebottom of links 34 are secured the separable counterweights 36.Counterweights may be added to or removed from the arm so that when agiven size wheel I2 is treated, the structure as a whole isapproximately balanced about the axis of shaft 8.

Arm 30 which may be of cast or welded construction, is generally ofI-section, having a flange 38 on one side thereof and a flange 40 on theother, and being provided with a central longitudinal web 42. The armisfurther strengthened by the provision of an upright transverse web 44as shown. The arm flares laterally from the shaft so that its outer endforms a gripper head of generally yoke shape, one leg of the yoke beingenlarged at 45 to form a supporting hub whose axis is parallel tothat ofshaft 8. The other leg of the yoke is likewise enlarged to provide ahousing 55 on the outside of flange 48, such leg also being providedwith an inwardly directed sleeve 52 having a cylindrical boretherethrough coaxial with the hub of enlargement 45. Positioned in thebore through sleeve 52 is an axially fixed spindle 54 mounted forrotstion therein, said spindle being driven by means of the sprocket 58located in housing 55, the sprocket being keyed to the spindle. Theinner end of spindle 54 may be squared or splined, if desired, tosupport and angularly position a cup-shaped gripper 58, the outer faceof which is suitably recessed therefor. Gripper 58 has a forwardwheel-engaging surface adapted to enagge one side of the hub thereof.

The opening through hub 45 above described is threaded, as shown, toreceive the outer threaded end of a fixed hollow cylinder 55, whichconstitutes the piston of a fluid operated reciprocating motor foradvancin and retracting a movable wheel mounting cup-shaped gripper 84.Also screwed in the outer end of the bore in hub 45 is a plug 52 havinga port 54 therein for the admission and exhaust of the fluid foroperating the motor from a, source not shown. Slidably mounted upon theouter surface of piston 55 is a movable cylinder 55, there being apacking 58 between the piston and cylinder, such packing being held inplace by a gland l5. Cylinder 55 is provided at its inner end with atransverse wall 14 from which there projects outwardly a centrallylocated stem 12. A spindle 85 having the gripper 84 thereon is journaledin the stem. On the threaded outer end of the stem is amxed a cap makinga fluid-tight connection therewith. By this construction, upon theadmission of fluid under pressure through port 54 by means of a valve(not shown), cylinder 55 is moved inwardly to carry gripper 84'intowheel-engaging position. On release of the pressure on the fluid, thecylinder is retracted by a coil spring 18 surrounding the stem andcompressed between a ring 85. welded to the inner end'of piston 55, andthe rim 82 of cap 15.

Spindle 85 is restrained from axial movement with respect to thecylinder by an enlarged head 88 on the outer end thereof disposedbetween the inner end of stem I2 and a thrust bearing 95 in cap I5.Thus, gripper 84 is supported in the cylinder 55 for idle rotation witha wheel gripped between it and gripper 58 by rotation of the spindle 54.This spindle is driven by motor II5 mounted upon shaft 8 through asprocket I I! on the motor shaft, a sprocket 55 on the spindle and aconnecting chain H4.

The stationary sleeve 52 is provided on its inner end with a shield 52,in the form of a disc, which is of approximately the same diameter asthe wheel and lies substantially parallel to the web plate thereof. Theinner wall 14 of cylinder 55 is likewise provided with a shield 94somewhat larger diameter than the wheel, and havin upon its outer edgean outwardly directed flange 95 substantially coaxial with cvlinder 55.Supported upon shield 92 are a plurality of burner nozzles 58 and apluralitv of water spray nozzles I55, each set of nozzles being soarranged that the flames and water sprays therefrom, respectively, coverthe entire area of the web plateprovided with two straight pipe sectionsI58 leading thereto being bolted to the flange 85.

In Figure 4 there is shown the portion of the wheel gripping means inthe vicinity of the wheel grippers 58 and 84 in the position they assumewhen the gripping means is open for the reception of a wheel to be heattreated. It will be apparent that the travel of cylinder 55 is such thatretractable gripper 84, together with shield 94 and arcuate conduitsI55, are retracted sufficiently so that the wheel may be introduced inIii a vertical straight line between the grippers by the telpher cranegripper. I

A preferred method of quenching employing the apparatus shown in Figures1 to 5, inclusive, is as follows:

The wheel is heated in a conventional furnace to a uniform overalltemperature of between 1500 to 1650 F. Itis then withdrawn from thefurnace, turned to an upright position by conventional wheel handlingapparatus. gri p d by the telpher crane gripper 28, and transported tothe wheel gripper and manipulator at the heat treatin station. The wheelis then gripped as shown in Figure 5, wheel turning motor H5 is thenstarted to rotate the wheel, the speed of rotation being, for instance,from 30 to 50 revolutions per minute. The wheel gripper and manipulatoris then lowered from the wheel loading position shown in Figure 2 to thequenching position shown in dotted lines at the right in that figure. Insuch quenching position a portion of the wheel rim dips into the waterbath to effect quenching thereof. Preferably the rim is immersed in thebath to such a depth that from A; to /2 inch of the inner rim remainsabove the bath. The wheel is left in that position until at least to /1of the rim has been transformed by quenching. which may take from 1 to 3minutes, the web plate I! of the wheel meanwhile being maintained aboutthe transformation point if necessary, by the application of heatthereto from burner nozzles 95 and I52 which immediately vaporize anywater which may fall upon the web plate during quenching of the rim.Rotation of the wheel likewise aids in removin water from the plate. Theseverity of quenching of the rim and particularly of the tread isincreased by the application of tread quenching sprays to tread I5 ofthe wheel by means of the arcuate spray pipes I55. When the rim has beensufficiently transformed, the heating flames from nozzles 98 and I52 areshut off, and the gripp r is then rotated about shaft 8 by, actuation ofmotor I4 to withdraw the wheel from the water bath and to completelyimmerse it in the oil bath 25, as shown in dotted lines at the left inFigure 2. where it may be left until the plate is completelytransformed, which may take from 1 to 4 minutes, depending upon thethickness of the plate, wheel section, and the character of the finalstructure desired in the plate. During such second web plate quenchingoperation, the wheel may or may not be rotated, as desired, by operationof 7 motor IIB. It is preferred that it be rotated, however, to agitatethe bath and to secure greater speed and uniformity of quenching. Afterbeing thus quenched in the oil bath, the wheel is withdrawn, removedfrom the gripper, and is drawn at temperatures of from 700 to 980 F.after which it is slowly cooled.

As a result of such treatment, it will be found that tread I of thewheel, indicated in Figure 4, which has been most drastically quenched,is very hard, that the remainder of rim I3 is tough and shock resistant,that web plate I'I, having been less drastically quenched in the oilbath,

is resilient and resistant to fatigue, and that huh I 9, especially inthe portion abutting the bore 2I therethrough, remains in a relativelysoft machinable condition due to its having been covered on its innerportions by grippers i8 and It. The residual stresses produced in wheelsso treated closely approach those of the desirable residual stressesfound in rim toughened wheels.

A wheel so treated therefore combines the advantages of the resistanceto thermal cracking and plate failure caused by brake application,characteristics of the rim toughened wheel and the fatigue resistance toplate failure of the oil quenched wheel.

The above preferred method of heat treatingas before in the loadingposition A, and may then be lowered into the positionB, wherein aportion of the rim is immersed in the water bath. If desired, the platemay, as before, be heated as by the burners 98 and I02 when the wheel isin position B. After a predetermined period of quenching the rim, whichmay take from 1 to 3 minutes in order to transform from /2 to of therim, gripper 6 is lowered to bring the wheel into the position C, shownin Figure 6", so that the entire wheel with the exception of thatportion of the hub blanketed by grippers I8 and It may be drasticallyquenched.

4 The method may further be varied, if desired, by the modification ofthe second, plate quenching, step of the method depicted in Figures 6and 6 in the manner illustrated in Figure 7. As there shown, the wheel.in the second. plate quenching, step, is lowered into the water bath Hito a depth such that the bottom portion of the plate of the wheel issubstantially wholly immersed in the bath, but the hub and the hubengaging members of the gripping and manipulating device remain abovethe bath. By the use of the last described second quenching step, thehub and portion of the plate immediately adjacent it are slightly softerthan they are when the wheel is completely immersed, because they aresomewhat less drastically cooled.

The method may be additionally varied, when using the water sprayquenching alone, by substituting the operation depicted in Figure 8 forthat shown in Figure 6 In this case, instead of being immersedcompletely in the water bath, the wheel remains in the position B, shownin Figure 6, but the heating flames directed upon the plate are cut onand water sprays from nozzles 8 l 3100 and I are played upon the plate,as shown A Figure 8. In this modification the tread quenching spraysfrom annular pipes Ill may be used with both the first rim quenchingstep and also the plate quenching step, or for example the treadquenching nozzles may be shut off when performing the second, platequenching operation, shown in Figure 8, if desired.

In some cases it is desired to employ heat treatments of railway wheelsinvolving quenching of the rim and plate in oil baths alone. For thistype of treatment, the apparatus shown in Figures 9, 10, and 1.1 hasproved very satisfactory. The parts thereof which are similar to thosein the structure shown in Figures 1 to 5, inclusive, are similarlydesignated but with primed characters. In this modification, a tank 8containing an oil bath I20 is employed, over which the wheel gripper andmanipulator is pivoted on the transverse shaft I 24, to allow movementof the wheel gripped thereby from a position above the bath, for loadingand unloading of the fixture, to a position in which the wheel is fullyimmersed in the bath. Due to the fact that but one quenching tank isemployed, trunnions I26 carrying the shaft I24 may be located close tothe arm I22 of the gripper, and the counterweight arm I28 may bepositioned generall as an extension of arm I22. Depending from the rearend of the counterweight arm are links 34 to which are attached theseparable counterweights 36. The apparatus for tilting arm I22 of thegripper in this instance consists of a crank I 30 driven by a motorthrough a suitable reduction gear (not shown), so that the crank can beturned to vari ous angular positions. Crank I" is connected to thecounterweight arm I28 by a pitman I32 con nected to the arm by pivot pinI34.

In this modification the means for supporting wheel I2, for rotating it,and for advancing and retracting the movable gripper means 84 are thesame as those in the first modification, and need not be particularlydescribed.- The present apparatus differs from that of the firstmodification primarily in the provision of rotatable wheel rim engagingshields I36 and I38, which are advanced against the wheel to shield theweb plate during the rim quenching operation, and are retractedtherefrom to expose the web plate to the quenching action of the oilbath in the second step of the operation. The retractable shield I" ispositioned for rotation and axial sliding movement upon the outercylindrical bearing member I40 which is attached to the front wall 14'of the cylinder 66 and extends outwardly, as shown. Shield I36 issupported for rotation and axial movement upon the similar cylindricalbearing member I 46 attached to the radially directed flange I on theforward end of sleeve 62'. Shields I36 and I38 are frictionally drivenby wheel I2 when in engagement therewith.

The shields are moved axiall to advance them toward the wheel andretract them therefrom by means of the annular ribs I48 and I50,extending radially therefrom, such ribs being engaged by shield shiftingmechanism constructed as follows: Arm I22 is provided with twovertically extending elongated bosses I 52 and I" through the bores inwhich extend vertical shafts I". Each shaft has keyed to the bottomthereof a shield shifting lever I", shown in Figure 9, and each levercarries on its outer end a pivotally mounted shoe having a groovetherein fitting over the corresponding annular rib on the shield; Bellcranks I62 and I68 are secured to the upper ends ripping means.

of shafts I58, respectively. Each bell crank has an arm such as I64extending toward the shield, such arm carrying on its outer end apivotally mounted shoe engaging the annular rib of the shield. Each bellcrank is also provided with an arm I66 extending generally axially ofthe wheel The inner ends of both arms have elongated slots engaged by acommon pin extending through the clevis I10. The clevis in turn isattached to the outer end of piston rod I12 of the double acting fluidactuated motor I 14. The arrangement is such that upon actuation of themotor I14 to thrust piston rod I12 outwardly thereof, shields I36 andI38 are retracted from the wheel, whereas upon travel of piston rod I12inwardly of the motor, the shields are brought into engagement with therim of the wheel.

In order to insure the retention of the web plate of the wheel at atemperature above the transformation point during the quenching of therim, there are provided heating means interiorly of the space providedby the retractable shields and the wheel gripping means. In themodification shown, the heating means takes the form of high frequencyinduction coil heaters I16 and I80, coil I16 being affixed to the innersurface of flange I44 and coil I80 being attached to the inner surfaceI42 of the forward wall 14' of cylinder 66'.

Such coils, which are conventional in design, may

be supplied with current'through leads, such as I18 for coil I16 and I82for coil I80.

Rotation of the wheel when engaged by the gripper and manipulator iseffected in this instance by means of sprocket I84 idly mounted upon theend of shaft I24, and connected to sprocket 56' by means of chain II 4'.Sprocket I84 is in turn driven b means of sprocket I86, likewise idlymounted 'upon shaft I24, the two sprockets being secured together asshown, and being retained upon the shaft by means I88. Sprocket I86 isrotated by means of a suitably geared motor (not shown) attached to aconvenient part of the rigid foundation.

The operation of the apparatus shown in Figures 9, I0, and II incarrying out a preferred method employing oil quenching alone isdepicted in Figures 12* and 12. As shown in the first of these figures,the wheel I2, which is at a temperature above its transformationtemperature,

when engaged in the gripper and with the shields I36 and I30 heldtightly thereagainst is set into rotation and is completely immersed inthe oil bath. Ordinarily the heating coils I16 and I80 are operated tomaintain the web plate at a temperatur above its transformation pointduring the rim quenching operation, but in some instances this may bedispensed with. Thereupon the rim of the wheel, since it is directly incontact with the oil, is progressively quenched. It has been found thatoil seepage between the wheel and the shields is negligible if anappreciable pressure between shields and wheel is employed. In anyevent, oil seeping into the closed space is quickly vaporized because ofth high temperature of the plate, thereby creating a positive pressurewithin the closed space which effectively prevents further oil seepage.

The apparatus is maintained in th condition shown in Figure 12preferably for a time suitable to allow transformation of from to of thewheel rim. Thereupon the plate heating coils are shut off, and theshields I36 and I38 are retracted to allow the quenching oil bath tocontact the entire wheel with the exception of the hub portion blanketedby the gripping means,

The wheel may be rotated, in such second quenching operation, ifdesired, but this is not necessary. Rotation of the wheel during suchoperation is to be preferred, however, to agitate the bath and to securegreater speed and uniformity of quenching. The wheel is allowed toremain in the bath, as shown in Figure 12 for a period suitable toaccomplish complete transformation of the plate and the outer portion ofthe hub. Thereupon the wheel is removed from the bath and is drawn bybeing heated and cooled in the manner above disclosed in connection withthe combined water and oil quench.

Having thus fully described preferred embodiments of my improvedapparatus for heat treating wheels, I desire to claim as new thefollowing.

I claim:

1. In railway-wheel heat-treating apparatus, a tilting manipulator armhaving a gripper head at the outer end for holding the wheel androtating it while it is subjected to quenching, said gripper headincluding spaced opposed wheel-engaging members journaled in the head,one of said members being slidable toward and from the other, saidmembers engaging the wheel on opposite sides thereof at the hub andbeing adapted to shield the hub from contact with the quenching medium,and means for tilting said arm toward and from a quenching bath.

2. In railway-wheel heat-treating apparatus, the combination with twospaced tanks containing quenching baths, of a tilting arm between saidtanks having a wheel-supporting head for holding the wheel and rotatingit while it is subjected to a rim-quenching operation in one bath and aweb-plate-quenching operation in the other bath, said head beingadapted. to place a wheel held thereby selectively in quenchingrelationship with either quenching bath, and spaced 0p posedwheel-engaging members journaled on the head for supporting the wheelfor rotation about its axis and adapted to shield the hub of the wheelfrom contact with the quenching media.

3. Apparatus as defined by claim 1 characterized by means mounted onsaid arm driving one of said wheel-engaging members.

4. Apparatus as defined by claim 1 characterized by said head includingspaced discs, one adjacent each of said wheel-engaging members andcoaxial therewith, and fluid-discharge nozzles mounted on said discsdirected onto the web of a wheel engaged by said members.

5. In railway-wheel heat-treating apparatus, a quenching bath, a tiltingarm extending over the bath for holding the wheel and rotating it whileit is subjected to quenching, said arm being yokeshaped at the outer endforming a wheel-gripping head and including spaced opposed grippersjournaled thereon adapted to engage the wheel and support it forrotation about its axis, said grippers overlying the hub of the wheel toshield it from contact with the quenching medium, and means for tiltingarm to lower the head and immerse the wheel in the bath to the desireddepth or raise it out of the bath for placing the wheel in' or removingit from the head.

6. In railway-wheel heat-treating apparatus, a quenching bath, a tiltingarm extending over the bath for holding the wheel and rotating it whileit is subjected to quenching, said arm being yokeshaped at the outer endforming a wheel-gripping headand including spaced opposed grippersjournaled thereon adapted to engage the wheel and support it forrotation about its axis, a pair of spaced opposed shields on the headfor protecting the web plate of the wheel from contact with thequenching medium, said shields being movable along the axis of the wheeland adapted to engage the wheel and to form closed spaces on each sideof the wheel when pressed thereagainst, and shifting mechanism forselectively moving the shields toward and from the wheel.

7. Wheel-quenching apparatus comprising a shaft joumaled horizontallyadjacent a quenching tank, an arm mounted on the shaft for tiltingtoward and from said tank, said arm having spaced aligned sleeves at theouter end, a pair of spaced aligned rotatable grippers journaled one ineach sleeve and a guide on said arm extending coaxially of the grippers,one of said sleeves being slidable axially on said guide.

8. The apparatus defined by claim 7 characterized by said guide being apiston fixed on the arm, said one of said sleeves having a cylindersliding on said piston.

9. The apparatus defined by claim 7 characterized by means mounted onthe shaft for driving one of said grippers.

10. The apparatus defined by claim 7 characterized by spaced generallycylindrical shields mounted coaxially with said .sleeves, each shieldsurrounding one gripper and being movable axiall thereof.

11. The apparatus defined by claim 10 characterized by shiftingmechanism for moving the shields toward and from each other.

12. The apparatus defined by claim 11 char- 12 acterized by a singleactuator common to the shifting mechanism of both shields.

13. The apparatus defined by claim 10 characterized by said shieldsbeing rotatable on said sleeves.

14. The apparatus defined by claim 10 characterized by each sleevehaving a coaxial bearing cylinder adjacent its gripper, said shieldsbeing slidable and rotatable on said cylinders, respectively.

HAROLD B. WISHART.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 871,931 Hansen Nov. 26, 1907922,655 Woll May 25, 1909 1,071,012 Unger Aug. 19, 1913 1,276,106 Peaseet al Aug. 20, 1918 1,391,907 Schafier Sept. 27, 1921 1,520,676 KoppinDec. 23, 1924 1,704,327 Kenney et a1 Mar. 5, 1929 1,711,835 Davis May 7,1929 1,859,623 Gregg May 24, 1932 2,167,185 Preston July 25, 1939FOREIGN PATENTS Number Country Date 685,087 Germany Dec. 11, 1939

